1) You have the problems that different developers have different styles. So when you jump from one area to another in the code base you're hit with WFT this is functional/procedural/inheritiance/composition, etc. style and your first thought is "barf" they did it wrong...
2) People either have huge functions that are spaghetti or tiny little functions to avoid complexity that are one line if statements.
Both of these are usually rooted in lack of a shared code culture, these are not SPA issues but team issues.
